<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

defined('THINK_PATH') or exit();
/**
 * Sqlsrv数据库驱动
 * @category   Extend
 * @package  Extend
 * @subpackage  Driver.Db
 * @author    liu21st <liu21st@gmail.com>
 */
class DbSqlsrv extends Db{
	protected $selectSql  =     'SELECT T1.* FROM (SELECT thinkphp.*, ROW_NUMBER() OVER (%ORDER%) AS ROW_NUMBER FROM (SELECT %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING%) AS thinkphp) AS T1 %LIMIT%%COMMENT%';
	/**
	 * 架构函数 读取数据库配置信息
	 * @access public
	 * @param array $config 数据库配置数组
	 */
	public function __construct($config='') {
		if ( !function_exists('sqlsrv_connect') ) {
			throw_exception(L('_NOT_SUPPERT_').':sqlsrv');
		}
		if(!empty($config)) {
			$this->config	=	$config;
		}
	}

	/**
	 * 连接数据库方法
	 * @access public
	 */
	public function connect($config='',$linkNum=0) {
		if ( !isset($this->linkID[$linkNum]) ) {
			if(empty($config))	$config  =  $this->config;
			$host = $config['hostname'].($config['hostport']?",{$config['hostport']}":'');
			$connectInfo  =  array('Database'=>$config['database'],'UID'=>$config['username'],'PWD'=>$config['password'],'CharacterSet' => C('DEFAULT_CHARSET'));
			$this->linkID[$linkNum] = sqlsrv_connect( $host, $connectInfo);
			if ( !$this->linkID[$linkNum] )  $this->error(false);
			// 标记连接成功
			$this->connected =  true;
			//注销数据库安全信息
			if(1 != C('DB_DEPLOY_TYPE')) unset($this->config);
		}
		return $this->linkID[$linkNum];
	}

	/**
	 * 释放查询结果
	 * @access public
	 */
	public function free() {
		sqlsrv_free_stmt($this->queryID);
		$this->queryID = null;
	}

	/**
	 * 执行查询  返回数据集
	 * @access public
	 * @param string $str  sql指令
	 * @return mixed
	 */
	public function query($str) {
		$this->initConnect(false);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		//释放前次的查询结果
		if ( $this->queryID ) $this->free();
		N('db_query',1);
		// 记录开始执行时间
		G('queryStartTime');
		$this->queryID = sqlsrv_query($this->_linkID,$str,array(), array( "Scrollable" => SQLSRV_CURSOR_KEYSET));
		$this->debug();
		if ( false === $this->queryID ) {
			$this->error();
			return false;
		} else {
			$this->numRows = sqlsrv_num_rows($this->queryID);
			return $this->getAll();
		}
	}

	/**
	 * 执行语句
	 * @access public
	 * @param string $str  sql指令
	 * @return integer
	 */
	public function execute($str) {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		//释放前次的查询结果
		if ( $this->queryID ) $this->free();
		N('db_write',1);
		// 记录开始执行时间
		G('queryStartTime');
		$this->queryID=	sqlsrv_query($this->_linkID,$str);
		$this->debug();
		if ( false === $this->queryID ) {
			$this->error();
			return false;
		} else {
			$this->numRows = sqlsrv_rows_affected($this->queryID);
			$this->lastInsID = $this->mssql_insert_id();
			return $this->numRows;
		}
	}

	/**
	 * 用于获取最后插入的ID
	 * @access public
	 * @return integer
	 */
	public function mssql_insert_id() {
		$query  =   "SELECT @@IDENTITY as last_insert_id";
		$result =   sqlsrv_query($this->_linkID,$query);
		list($last_insert_id)   =   sqlsrv_fetch_array($result);
		sqlsrv_free_stmt($result);
		return $last_insert_id;
	}

	/**
	 * 启动事务
	 * @access public
	 * @return void
	 */
	public function startTrans() {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		//数据rollback 支持
		if ($this->transTimes == 0) {
			sqlsrv_begin_transaction($this->_linkID);
		}
		$this->transTimes++;
		return ;
	}

	/**
	 * 用于非自动提交状态下面的查询提交
	 * @access public
	 * @return boolen
	 */
	public function commit() {
		if ($this->transTimes > 0) {
			$result = sqlsrv_commit($this->_linkID);
			$this->transTimes = 0;
			if(!$result){
				$this->error();
				return false;
			}
		}
		return true;
	}

	/**
	 * 事务回滚
	 * @access public
	 * @return boolen
	 */
	public function rollback() {
		if ($this->transTimes > 0) {
			$result = sqlsrv_rollback($this->_linkID);
			$this->transTimes = 0;
			if(!$result){
				$this->error();
				return false;
			}
		}
		return true;
	}

	/**
	 * 获得所有的查询数据
	 * @access private
	 * @return array
	 */
	private function getAll() {
		//返回数据集
		$result = array();
		if($this->numRows >0) {
			while($row = sqlsrv_fetch_array($this->queryID,SQLSRV_FETCH_ASSOC))
			$result[]   =   $row;
		}
		return $result;
	}

	/**
	 * 取得数据表的字段信息
	 * @access public
	 * @return array
	 */
	public function getFields($tableName) {
		$result =   $this->query("SELECT   column_name,   data_type,   column_default,   is_nullable
        FROM    information_schema.tables AS t
        JOIN    information_schema.columns AS c
        ON  t.table_catalog = c.table_catalog
        AND t.table_schema  = c.table_schema
        AND t.table_name    = c.table_name
        WHERE   t.table_name = '$tableName'");
		$info   =   array();
		if($result) {
			foreach ($result as $key => $val) {
				$info[$val['column_name']] = array(
                    'name'    => $val['column_name'],
                    'type'    => $val['data_type'],
                    'notnull' => (bool) ($val['is_nullable'] === ''), // not null is empty, null is yes
                    'default' => $val['column_default'],
                    'primary' => false,
                    'autoinc' => false,
				);
			}
		}
		return $info;
	}

	/**
	 * 取得数据表的字段信息
	 * @access public
	 * @return array
	 */
	public function getTables($dbName='') {
		$result   =  $this->query("SELECT TABLE_NAME
            FROM INFORMATION_SCHEMA.TABLES
            WHERE TABLE_TYPE = 'BASE TABLE'
            ");
		$info   =   array();
		foreach ($result as $key => $val) {
			$info[$key] = current($val);
		}
		return $info;
	}

	/**
	 * order分析
	 * @access protected
	 * @param mixed $order
	 * @return string
	 */
	protected function parseOrder($order) {
		return !empty($order)?  ' ORDER BY '.$order:' ORDER BY rand()';
	}

	/**
	 * limit
	 * @access public
	 * @param mixed $limit
	 * @return string
	 */
	public function parseLimit($limit) {
		if(empty($limit)) return '';
		$limit	=	explode(',',$limit);
		if(count($limit)>1)
		$limitStr	=	'(T1.ROW_NUMBER BETWEEN '.$limit[0].' + 1 AND '.$limit[0].' + '.$limit[1].')';
		else
		$limitStr = '(T1.ROW_NUMBER BETWEEN 1 AND '.$limit[0].")";
		return 'WHERE '.$limitStr;
	}

	/**
	 * 更新记录
	 * @access public
	 * @param mixed $data 数据
	 * @param array $options 表达式
	 * @return false | integer
	 */
	public function update($data,$options) {
		$this->model  =   $options['model'];
		$sql   = 'UPDATE '
		.$this->parseTable($options['table'])
		.$this->parseSet($data)
		.$this->parseWhere(!empty($options['where'])?$options['where']:'')
		.$this->parseLock(isset($options['lock'])?$options['lock']:false)
		.$this->parseComment(!empty($options['comment'])?$options['comment']:'');
		return $this->execute($sql);
	}

	/**
	 * 删除记录
	 * @access public
	 * @param array $options 表达式
	 * @return false | integer
	 */
	public function delete($options=array()) {
		$this->model  =   $options['model'];
		$sql   = 'DELETE FROM '
		.$this->parseTable($options['table'])
		.$this->parseWhere(!empty($options['where'])?$options['where']:'')
		.$this->parseLock(isset($options['lock'])?$options['lock']:false)
		.$this->parseComment(!empty($options['comment'])?$options['comment']:'');
		return $this->execute($sql);
	}

	/**
	 * 关闭数据库
	 * @access public
	 */
	public function close() {
		if ($this->_linkID){
			sqlsrv_close($this->_linkID);
		}
		$this->_linkID = null;
	}

	/**
	 * 数据库错误信息
	 * 并显示当前的SQL语句
	 * @access public
	 * @return string
	 */
	public function error($result = true) {
		$errors = sqlsrv_errors();
		$this->error    =   '';
		foreach( $errors as $error ) {
			$this->error .= $error['message'];
		}
		if('' != $this->queryStr){
			$this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
		}
		$result? trace($error['message'],'','ERR'):throw_exception($this->error);
		return $this->error;
	}
}